


False Determination

by The_Dancing_Demon



Category: Undertale (Video Game)
Genre: F/M, Fluff, GASTER IS CREEPY BOI, Maybe kissing later, No Smut, Papyrus is a cinnamon roll, Spookyscaryskeletons, Stuff, alphys is cute, dont hate me if i mess up, idk - Freeform, just offer good advice and critiques, myfirstwork, pleasedontbemean, semi-canon, some of my own headcanon, toriel is ultimate mom, undyne is a bit of a bitch
Language: English
Status: Completed
Published: 2020-01-17
Updated: 2020-01-30
Packaged: 2021-02-27 06:15:09
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 10
Words: 3,414
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22292413
Author URL: https://archiveofourown.org/users/The_Dancing_Demon/pseuds/The_Dancing_Demon
Summary: You, the reader, are a skeleton, artificially made, using determination from a human soul. Your soul is purple. You are filled with PERSEVERANCE.Sans has been your best friend since childhood, and you've loved him through every timeline, remembering all of the deaths, knowing that none of it was to last.Idk i was bored and wanted to introduce my OC.Have fun?
Relationships: Flowey / Reader---ish, Sans (Undertale) / OC Reader, Sans (Undertale)/Reader
Comments: 4
Kudos: 19





	1. The Skeleton's Story

**Author's Note:**

> Hey, guys! Backstory chapter today. Expect updates on this story as often as I can. It will not be regular. This is just to get you familiar with Liz's past. Thanks!

Once, there was a scientist that worked alongside Dr. Gaster. Her name was Elizabeth A. Pennly. Her font was Abscissa. Her mother held a legacy, a vow to break free into the surface world.  
And yet, she could not do it. Her soul was not strong enough.  
One night, when the sky was black and the underground was dormant, she stole a human soul and used the DETERMINATION to create...  
A child.  
She made the child have the strength of seven human souls, all put into one upside-down heart, hoping that maybe this child could be queen of the underground.  
That this child would set them all free.  
This child could be a GODDESS...  
When the child was age eight, Dr. Pennly was running all of the tests she could to figure out the child's dreams of the future, the past, and even alternate realities, when Dr. Gaster discovered her work.  
"You cannot do this to a child! You created her, so you must treat her like your own!" Dr. Gaster protested.  
"I can do whatever I wish. It is MY experiment. It is NOT a true monster like the rest of us. She will break the barrier, and then we can all be free of the shackles that humanity has put on us!" Pennly argued.  
Dr. Gaster walked away, and then, being the Royal Scientist, was able to confiscate the child, and had the Queen take care of her, having Sans as a playmate, and the most caring mother of all as her caretaker.  
Not long after, Dr. Pennly died of a lab accident, Gaster got transported to the void, and the child and Sans, along with a baby skeleton named Papyrus, made their way out into the world to try and live.  
Four years later, after Sans and Papyrus had settled in Snowdin, the child, now named Lizzie, left to go to Waterfall, and lived with her friend Undyne for another four years.  
Undyne ended up betraying Lizzie's trust for her own personal gain, though, and at age sixteen, Liz has headed back to Snowdin...


	2. The Journey Begins

**Summary for the Chapter:**

> Just a regular day in the life of Liz.  
> also there are so many characters i forgot to tag so sorry! :(

**Notes for the Chapter:**

> hey this is updating sooner than i thought, heh. weekends will be a NO UPDATE ZONE. Sorry, and hey, have you seen...   
> . . .s n o w y ? h e h . . . h e h . . .  
> idk i bored

My alarm goes off, and using my psychokinesis, I throw it against the wall.  
"Argh..." I groan, and roll out of bed, teleporting to the couch before I hit the ground.  
"Guess it's time to start my day," I mumble, and teleport to the fridge to grab a plate of Pap's spaghetti and a bottle of ketchup.  
I then turn on the TV to the Mettaton cooking channel as I grab a fork, and sit down on the couch to eat.  
"And then you just add some pepper and you have a cake! No baking required!" MTT shouts from the TV, and I roll my eyes.  
"Mettaton knows nothing about cakes. Even I can make a better cake than him," I mutter, then put my breakfast back in the fridge, and head over to Grillby's.  
"What'll you be having, Eliza?" Grillby asks, his voice like the warmth of a crackling campfire.  
"Eh, Liquid Courage, if you don't mind. I need something to get me going," I say, and he grabs a bottle from under the counter and pours it into a shot glass.  
Just then, the door swings open, and I already know who it is.  
"H-Hey, Sans!" I stammer, and he sits on the bar stool next to me, flashing me a grin.  
"Heya, bud. How are ya today?" He asks me, and I gulp.  
"P-Pretty good, I guess. Just a bit tired, y'know?" I explain, looking down into my glass.  
"I know all about that. I take naps all the time," Sans chuckles, taking a swig from a bottle of ketchup that Grillby handed to him.  
Then someone else enters the bar.  
The human.  
Frisk.  
I can see the faint outline of Chara behind them, and I glare hard, Sans having to elbow me to stop.  
"Hey, kid! Lookin' for a drink? Or some food?" Sans asks, and Frisk shakes their head 'no'.  
Frisk then points to me, and does a confused expression.  
"Oh! You don't know who I am, do ya, buddy?" I exclaim, then lean in close to them so that no one else can hear, "I know who you are. I know who's guiding your hand. I know what you've done. You'd better stop now," my face goes dark, my eyelights disappearing, "OR I'LL HAVE A GREAT TIME KILLING YOU OVER AND OVER UNTIL YOU LEARN YOUR LESSON."  
I sit back up, beads of sweat dripping down the human's face, and they walk out.  
"What did you say to them?" Sans asked.  
"Nothing important. It's not like it's gonna interrupt the natural flow of the timeline that could have catastrophic consequences!" I laugh, and Sans looks concerned.  
"Eh..." I pay my tab and walk out, then take a nap at home on my couch.

**Notes for the Chapter:**

> hope u like thx for reading  
> peace bro  
> s n o w y ?


	3. A Little Talking Flower!

**Summary for the Chapter:**

> avert ur eyes, cinnamon rolls, for the flowey is a perv and something bad will happen to our favorite spaghet boi. rip.

**Notes for the Chapter:**

> yah hey here the worst/best flower ever  
> also swearing for first time and death

I wake up to hear rustling coming from my room upstairs.  
I teleport to my doorway to see a certain yellow flower rifling through my underwear drawer, a white bra in one of his vine-hands.  
"Care to explain yourself?" I ask, snatching the bra away with psychokinesis.  
"Oh! Liz, I, uh..." A red blush BLOOMS [hey hey hey] across his face as he turns toward me.  
"Get. The fuck. Out," I growl, my eye flaming purple.  
"I... I just need to know why you'd even NEED a bra in the first place," Flowey says, looking at the floor.  
"I'm made of bones AND magic, thank you very much. Purply magic glowy bits. Now. Get. Out," I explain.  
Flowey's face is now BEET-RED [i love plant puns] and he LEAVES [im sorry plz kill me] through the floor.  
"My GOD! I hate that stupid flower," I mutter, and walk out into the snow.  
"Eliza!" Papyrus shouts from behind me.  
"Oh, hey, Pappy buddy. How are ya?" I ask, turning to greet him, but half of him is turning to dust, "Oh crap, Papyrus, who did this?"  
"The human, they... I thought they could do better, but..." He coughs up some blood, and more of him disintegrates, "I s-till believe in them, but... Eliza, can you help me?"  
Tears start to roll down my cheekbones and I stammer, "N-no, I can't help to heal you, Papyrus, b-but... I can kill the human. Once the human kills Sans I can interrupt the timeline flow and kill them..." I trail off, seeing Papyrus's face.  
"E-Eliza, no. Just, p-please, take my scarf..." Papyrus takes it off and hands it to me, "and m-make sure that everyone c-can stay safe..."  
"I promise, Papyrus," I murmur, wrapping the scarf around my neck, "I will avenge you."  
Papyrus then fully dissipates, and I compose myself.  
'I don't care about the timeline,' I think, 'that human's gonna DIE.'

**Notes for the Chapter:**

> gotta love dat flowey, right?  
> ... im sorry pappy...  
> ...i was making this up as I went along at first, but now i has plan.  
> s n o w y ?


	4. If Only You Could Know

**Summary for the Chapter:**

> Liz is on a journey to follow the human, so that perhaps she can dissuade them from this genocide, or maybe, in the end, kill them once and for all.

**Notes for the Chapter:**

> hey guys this chapter's pretty short since i'm dealing with a bunch of other school stuff right now. hope ya like it i guess...

Holding Papyrus's scarf, I teleport to Waterfall just in time to see Frisk turn the corner away from me.  
"There," I whisper to myself, seeing the flowers set up by Flowey already.  
"That fucking coward," I swear, walking across, seeing the ripples in my reflection on the water.  
Then I see the human turn around just barely, see me, and run.  
"Heh. Human thinks they can just escape, huh?" I mutter, teleporting in front of them, then initiating a fight, "You're really funny, y'know. Thinking you can just escape the consequences, live on like normal, killing monsters without a second thought. I'm not gonna kill ya," I chuckle,"yet. For now, just take a look at your surroundings. This peace. This quiet."  
The human looks around, but then Chara's face replaces their own.  
"AREN'T YOU AN IDIOT," Chara growls, "FRISK IS TOO FAR GONE. THEY ARE UNDER MY CONTROL."  
"Okay, then, kid," I say, getting out of the fight, "Do what you want, I guess. Just know I'll be waiting at the end."  
I then teleport to Grillby's and help myself to some Liquid Courage.  
"I'm gonna need it," I murmur, staring at the label of the bottle, "Even if I die, I'll win."

**Notes for the Chapter:**

> i'm so FUCKING TIRED. dont expect another chapter today, or even tomorrow. bleh.


	5. Undyne the Undying

**Summary for the Chapter:**

> thx for comments and stuffs. heres undyne, and she a BIITTCHHH  
> (sorry for swearing)

I watch from the shadows as Frisk meets Monster Kid, then nearly kills them, but then I see her...  
"Undyne," I mutter under my breath and stride out, Papyrus's scarf flapping in the wind.  
"Liz?! What're YOU doing here?!" She cries, pointing a glowing blue spear at me.  
"Ugh, this human. Tryin' to stop 'em. Doubt you'll be able to, after showing me your real weakness so long ago," I say, "your SOUL."  
Undyne's face flushes red, contrasting her blue scaly-ish skin.  
"SHUT UP!!!" She shouts, and initiates battle with the human.  
"Undyne, at least let me help you. I'm sorry. I wanna be friends again," I admit, watching the flying spears.  
"No, you FUCKING BITCH!!!" Undyne screams, throwing more attacks at Frisk, who dodges easily.  
"I'M the bitch?! I'M THE BITCH?! You told fucking EVERYONE all the personal stuff I trusted you with! I told you that I loved Sans. And then you told EVERYONE!!! I trusted you, and you USED ME!!!" I protest, "and your soul is KINDNESS!!! I have no FUCKING IDEA how you DO THAT with a GREEN SOUL!!!"  
"I couldn't let people know!" Undyne shouted back, tears now streaming down her face, "People couldn't know my weakness! They couldn't learn that I was caring! To join the Royal Guard, I had to be tough. I couldn't..."  
"Undyne, the most courageous people are kind to others. I know you wanted to join the Royal Guard, and I encouraged you. You did it. But did you still have to shut me out? Can't we be friends?" I step forward, arms wide.  
Undyne sniffles, then her face goes blank, then it darkens.  
"No. I can't. We can't be friends. We're too different. I HAVE to kill this HUMAN---" Undyne gets cut off as the child's knife pierces through her armor and into her flesh.  
"Undyne! No!" I run over to her.  
"Go... the fuck... away..." She mutters, "and kill that damn kid."  
I nod, and stare Frisk down.  
"I said it before, and I'll say it again. I'll be waiting. Maybe if you change your mind, I'll make it hurt less," I growl as they back up slowly, then break into a run to escape my wrath.

**Notes for the Chapter:**

> thx for comment. love ya! <3


	6. To The Hotlands

**Summary for the Chapter:**

> Liz starts to break down as she follows Frisk to the Hotlands.  
> Another encounter with a petally friend.

**Notes for the Chapter:**

> idk. read the thing.

"Lizzie, Lizzie, Lizzie, following them as well, I see?" A voice says behind as I walk past the sign for the Hotlands.  
"Shut up, Flowey. It's for different reasons. You want to help. I want to hurt. To save us." I growl, quickening my pace.  
He then pops up in front of me.  
"Liz. We both know what you really want. You don't want to save all of us. You just want to save your smiley trash bag of a boyfriend," Flowey chirps.  
"He's not my BOYfriend, he's my BEST friend. I don't suppose you'd understand anything about that, would you?" I retort, walking past.  
"I... I had a best friend once," he murmurs, and I stop.  
"What?"  
"I... her name was Chara. We had the most fun we ever could've. When she fell, I helped her up... She was like my sister... But when she got sick and died, and I absorbed her soul..." Flowey trails off, looking down at his leaf-hands, "I died from the wounds that the human villagers inflicted on me. I became this. I would do anything for her. I don't REALLY want everyone to die. I just want Frisk to do this so I can see Chara again, y'know? I miss her..."  
As he starts to cry, I kneel down.  
"I'm sorry. I heard the story, but I hadn't realized you could still feel sorrow," I say, stroking his petals.  
"I can still feel emotion. In fact, they're more powerful than ever. I just can't let people see who I really am..." he chokes out between sobs.  
"Shh... Flowey, calm down... This isn't the way to see your Chara again. She's twisted, different. I'll be your friend for now," I offer, and Flowey looks up at me with tears in his eyes.  
"Y-You'll be my friend?" He stammers.  
"Of course, Flowey. I don't want people to die. I just want my friends to be safe. And I'll keep you safe, okay?" I ask, standing up.  
"O-Okay."  
Flowey clambers up onto my shoulder, wrapping his vines into a sort of harness so that he can stay balanced, and I start to walk further into the Hotlands.  
"Hey, Liz?"  
"Yeah, Flowey?"  
"I..." He blushes, then looks down, "Never mind."  
I glance at him with a skeptical look.  
"Okay, I guess," I mutter, looking ahead.

Flowey's POV  
\-------------------  
Damn, she's so beautiful.  
The way her black hair bobs when she walks, her glistening white eyelights...  
Wait, how does she have hair?  
Oh, probably a side-effect of the determination injections from when she was a child.  
I remember seeing her.  
I was so young...  
She was, too.  
And the moment I saw her...  
I fell for her.  
I can't ever tell her. She can't ever know.  
We'll just keep it a secret for now.

**Notes for the Chapter:**

> comment. leave kudos. do whatever u want, i not teh boss of u.


	7. Spider Dance

**Summary for the Chapter:**

> liz and flowey be walkin around when they see frisk and muffet doin their fighty thing. im sorry i so tired this mornin

**Notes for the Chapter:**

> tryna make chapters longer, guys. just want more detail and more for you to enjoy! thx for following this adventure of my first work!

Liz POV  
\------------------  
I realize that me and Flowey's conversation took up some time, so once we get to Alphys's lab, the human is already gone.  
"We'd better catch up soon," Flowey mutters, "they should be at Muffet by this point."  
I then teleport us to the entrance, hearing Muffet's theme playing.  
"Spider Dance," I whisper to myself, and slowly step into the doorway.  
"I'll SPARE you know," Muffet giggles.  
"Muffet, wait!" I shout, but the knife already sliced.  
Then the human turns to face me, and I glare.  
"I told you to stop," I growl.  
"NO," Chara protests, walking out from behind Frisk.  
"Ch-Chara?" Flowey stammers, and I poke him, reminding him of our conversation from earlier.  
"Asriel, you're a traitor now? That's a first. Normally you're the one to help me, to bring me back," she whispers, taking a step forward.  
"I-It's F-Flowey now, a-and what y-you're doing is wr-wrong!" Flowey spits at Chara, "Liz here is my best friend now."  
"Oh, well, it's not like it matters much anyway. You'll die in the end. That's how it always plays out, isn't it?" The demon girl explains, taking Frisk by the arm to lead them away.  
"No. We won't die. We'll kill you until you RESET," I say.  
"Sure... Of course you will..." Chara sarcastically calls, and soon, she's gone.  
"Flowey. Thanks for the backup," I say, and his face turns red.  
"What are friends for?" He mutters.  
"I've asked myself that over and over again," I explain, "and I guess it's just being there for them, right?"  
"You understand that that was a rhetorical question, right?" Flowey asks, and I nod.  
"Yeah. But I felt like telling you that," I say, and we walk out to stop Chara.


	8. MTT the Entertaining Killer Robot!!!

**Summary for the Chapter:**

> liz and flowey watch frisk fight mtt  
> poor mtt rip u join pappy in teh afterlife  
> i not religious i not believe in afterlife but who cares  
> it is also next to last chapter. next one is last and it will be out as soon as possible. remember to comment and leave kudos! thx!

**Notes for the Chapter:**

> MTT: Yas darling~ it is my chapter!  
> Me: Mettaton, I know you're in this chapter, but I'M the author.  
> MTT: Sure, but I'm the star!~  
> Me:... Fine. Whatever.

I can hear Mettaton's theme playing, and I shiver.  
"She's in her NEO form. She'll be killed in three, two..." I say, then hear the knife slash.  
"Liz, why aren't you doing anything about it? Aren't you trying to save them?" Flowey asks as I walk inside.  
"Flowey, you were right. I am trying to save Sans. I can't save anyone else. I'm gonna teleport us to the Last Corridor, okay?" I explain.  
"I... okay," he mutters, and in a flash of light, we're behind one of the pillars.  
Sans is standing as the human goes to the save point, then approaches.  
"Liz... Intervene now..." Flowey says, and I shrug him off of me, running in front of Sans.  
"Wha---Liz?!" Sans exclaims, and I glare.  
"Let me do this for you," I growl.  
"No, Liz, you're interrupting the flow of the timeline, there can be serious consequences, just let it----"  
"Shut the FUCK up! I'm doing this for you! I love you!!!" I shout, then add quietly, blushing, after seeing his expression, "like a brother."  
"Will YOU shut up?!" Chara asks, having completely taken over the human.  
"Fight me, bitch," I snarl, and she jabs the knife at me.  
I dodge easily, then summon my mom's dragon blasters, and fire lasers at them, killing them instantly.  
They come back, and this time, catch me off guard...  
"SANS, NO!!!"


	9. The Judgement Hall

**Summary for the Chapter:**

> last chapter, besides epilogue. no spoilers!!!

**Notes for the Chapter:**

> love ya all. thx for following me on this journey. will be plenty more fics after this.  
> btw i just figured out that rich text is cool, so i usin that now  
> another btw um flowey is kinds perverted here and cinnamon rolls beware

"SANS, NO!!!"

I scream as a pool of blood gathers on the floor from his wound.

"Liz... This is meant to happen... Stop getting so upset, okay?" Sans asks between fits of coughing out blood.

"But Sans, I... I want you to live. I want us to go to the surface. We HAVE to get there. We have to have a life together, I... I love you, Sans. Not like a brother. I've loved you since we were little," I explain, and Sans's eyelights widen.

"Liz, I've felt the same, but why? Why do you---" He coughs again, more blood spurting out, "Why are you telling me now?"

"Because I've never been more filled with PERSEVERANCE," I say, taking him in my arms.

"Y-You numbskull..." Sans murmurs, putting his hand behind my neck, bringing me closer.

"Bonehead," I reply, then we press our teeth together in the closest thing skeletons can get to a kiss.

The tang of blood hits my mouth as I pull away, and I can see Sans is turning to dust.

"Hey, n-next route, wanna head to Grillby's with me for a d-date?" Sans stammers, eyelights flickering.

"Of course, my love," I whisper, and he disintegrates in my arms.

Then I slowly stand up to face the human.

"Thank GODS that the sentiment is over," Chara grumbles, pointing her knife at me.

"You bitch. You wanna see us all die, huh? I'm not gonna let that happen," I snarl, and I turn to a skeledragon, no legs or arms, but great bone wings stretch out behind me as I grow to twenty feet.

"You motherfucker, using your determination like this? You know you're going to die," Chara retorts.

"Yeah, but I'mma give you one HELL of a bad time before I go out," I roar, but then vines wrap themselves around me, bringing me to the ground.

"Ch-Chara, look! I never betrayed ya!" Flowey exclaims, coming out from behind the pillar.

"Flowey! You SON OF A BITCH!!! LET ME OUT OR I SWEAR TO GOD, I WILL TEAR YOU APART OVER AND OVER AGAIN!!!" I bellow as his vines explore my bones, every ridge, every scar.

"Liz, I tricked you! Isn't that funny?~" Flowey cackles, tightening his grip on me, about to absorb my soul.

"Flowey, this isn't YOUR Chara! She's going to KILL you!" I scream, nearly laughing from Flowey messing around with my soul.

"Chara, do you want it?" Flowey asks her, and she shakes her head.

"Break it," she demands instead.

"I--- Maybe we can talk about this, she could be useful, and----" Flowey gets cut off.

"You IDIOT. Kill her already!" Chara shouts, and Flowey winces.

"S-Sorry," he says, and wraps a vine around the small purple upside-down heart, squeezing, squeezing...

My vision starts to blur and pain wracks through my body, making me roar.

I then just barely see cracks, and then...

Darkness.


	10. Epilogue

**Summary for the Chapter:**

> ...

**Epilogue**

**\---------------------------------**

"Ma...ma...!" Celeste, an infant skeleton, crawls towards me across the carpeted floor.

"Yes, it's me, your Mama," I say, picking her up to cradle her in my arms.

"Babe, I'm home," Sans's low voice says from the doorway, "I brought some food from Grillby's."

I stand up and walk over to him, "Oh, nice! How was ol' Grillbz?" I ask, taking one of the to-go bags from him. 

"Pretty good. He's still adjustin' to the human customers, though. The surface is still new to him," Sans explains, "even after three years."

"Hey, it's not like I can go a day without hearin' Megalovania and seein' a couple blasters leaving the lab. Then again, I guess you have the right to defend yourself from the racist-ass people," I mutter, sitting down at the dining room table, putting Celeste in her high-chair.

I adjust my glasses as Sans sits down, and I see a new scar on the vertebrae that make up his neck.

"Sans. Did this come from you-know-who?" I ask, tracing it with my phalanges.

"Yeah. Tried to talk to her today. Like always, just tried to attack. It's crazy what you managed to do, separating Chara from Frisk's soul," he explains.

"Well, we'll eventually get her to open up. For the good of monsters and humanity," I say.

"Speaking of which, Frisk was gonna host a formal dinner inviting all of us, and some of the human leaders. We gonna go?"

"Of course," I agree.

**The End**

**Author's Note:**

> Didja like it? Hopefully you did. Let me know in the comments, I guess.  
> Peace.


End file.
